1. Field of the Invention
The application relates to a semiconductor structure, and more particularly to a semiconductor structure having an oxide semiconductor channel layer.
2. Description of Related Art
Currently, the most ubiquitous type of liquid crystal display is mainly constructed with a thin film transistor array substrate, a color filter substrate and a liquid crystal layer sandwiched therebetween. On a conventional thin film transistor array substrate, amorphous silicon (a-Si) thin film transistor or low temperature polysilicon thin film transistor is typically used as a switching unit of each sub-pixel. In recent years, many studies have suggested that oxide semiconductor thin film transistor has higher field-effect mobility, and comparing with the low temperature polysilicon thin film transistor, the oxide semiconductor thin film transistor has better uniformity in the threshold voltage (Vth). Accordingly, the oxide semiconductor thin film transistor has the potential to become a critical device of the next generation flat display. However, under the framework of the conventional oxide semiconductor thin film transistor, it is difficult to further elevate the field-effect mobility.